It is found that the conventional P. A. T. (powder actuated tool) utilizes a trigger and a firing pin to actuate explosion thereby pushing a piston rod and striking a drive pin into a workpiece from the tool. However, such powder actuated tool is complicated in structure and often has trouble. Then a powder actuated tool without trigger, firing pin and piston has been developed to eliminate such drawbacks. Nevertheless, the withdrawing pin thereof is easily broken and the explosion force cannot be controlled to adapt to various kinds of working pieces.
Therefore, it is an object of the present invention to provide a powder actuated tool which may obviate and mitigate the above-mentioned drawbacks.